Apparatus for feeding two wires simultaneously

ABSTRACT

Wire feeding means comprises a pair of feed wheels mounted on parallel spaced-apart axes. One of the wheels has two tires mounted in side-by-side relationship on its periphery, each tire being adapted to engage one of two wires being fed. The tires are supported on the periphery of the wheel by means of helical springs which extend radially with respect to the axis of the wheel. These springs can be compressed and also can be deflected laterally thereby to permit the tires to feed different sizes of wires and to provide a resilient coupling between the tires and the wheel on which they are mounted.

United States Patent Charles Dale Steiner Harrisburg, Pa. 874,430

Nov. 6, 1969 May 1 l, 1971 AMP Incorporated Harrisburg, Pa.

[72] Inventor [21 Appl. No. [22] Filed [45] Patented [73] Assignee [54] APPARATUS FOR FEEDING TWO WIRES 2,953,291 9/1960 Huck 3,392,896 7/1968 Ullman ABSTRACT: Wire feeding means comprises a pair of feed wheels mounted on parallel spaced-apart axes. One of the wheels has two tires mounted in side-by-side relationship on its periphery, each tire being adapted to engage one of two wires being fed. The tires are supported on the periphery of the wheel by means of helical springs which extend radially with respect to the axis of the wheel. These springs can be compressed and also can be deflected laterally thereby to permit the tires to feed different sizes of wires and to provide a resilient coupling between the tires and the wheel on which they are mounted.

Patented May 11, 1971 I 3,578,228

2 Sheets-Sheet 2 BACKGROUND OF THE INVENTION produce two completed electrical leads during each operating.

cycle, rather than a single lead. It is necessary to feed'two wires to the machine during each operating cycle in order'to effect such adaptations.

Where the two wires being fed are of precisely the same diameter and are of uniform diameter throughout theirlengths, the feeding of two wires by a single pair of feed wheels presents no special problem. The feed. wheels will contact both of the wires arid feed the same length of each wireduring each operating cycle. However, if one of the wires should have a diameter slightly greater than that of the other wire, the larger wire may force the feed wheels apart to the extent that they will not engage the smaller diameter wire or the wheels will slip on the smaller diameter wire, a condition which will result in the feeding'of unequal lengths of thetwo wiresflt' should be addedthat a slight difference in the diameters of the two wires will result in the feeding of unequal wire lengths; in fact, the diameter variations which result from ordinary manu facturing tolerances are sufficient to result in the feedingfof unequal lengths of wire during a given operating cycle.

The solution to the problem outlined above is to construct at least one of the feed wheels in a manner such that bothj of the wires will becontinuously engaged even if there areslight variations in the diameters of the wires and/or one of the wires has a diameter which is slightly greater than that of the'other wire. The solution proposed in the above identified US. Pat. No. 3,392,896 is to mount a tiltable tire on one of :the feed wheels which tilts with respect to the plane of the feed wheel in response to a difference in the wire diameters thereby to en sure continuing contact of the wheel with both of the wires.

Feed wheels of the type shown in U.S. Pat. No. 3,392,896 have been found to". be satisfactory under most circumstances however it has been discovered that itwould desirable to feed two wires of substantially different diameters simultaneously;

in other words, it would be desirable to improve upon, andextend, the capacity of known two-wire feeding mechanisms to accommodate wiresof different nominal diameters.

It has also been recognized for some timethat intermittently operating feed wheels of the type used on lead makingmachines should advantageously be provided witha mi: sionally resilient coupling between the driving means for the feed wheels and the periphery or tire portions of the wheels which actually engage the wires. The provision of a torsionally' These and other objects of the invention are achieved in a preferred embodiment thereof which is briefly described in the foregoing abstract, which is described'in detailin the specification which follows,-and which is shown in the accompanying drawings in which;

FIG. 1 is a plan view of a set of feedwheels'in accordance with the invention illustrating the manner: in which such wheels maybe mounted on a lead making machine or the like.

FIG. 2 is a side view of the feed wheels of FIG. 1, with pans broken awayin order to show details, showing the positions'of the parts when the wheels are at rest.

FlG. 3 isa'sectional view taken along. the lines 3-3 of FIG. 2.

FlG. 4 is a fragmentary view on an enlarged scale showing the manner in which wires of different diameters can be accommodated by feed wheels in accordance with the invention.-

FIG. 5 is a view-similar to" FIG. 2 but showing the positions of the parts at the cornmencement'of a wire feeding operation.

FIG. 6 is a perspective exploded view of one of the feed wheels of the feeding mechanism of FIG. '1.

Wire feed wheels for lead making machines of the general type shown, for example, in the U.S. Fat. to Schwalm, et al. 3,0l9,679 are ordinarily mounted on the machine in the manner shown in FIG. 1. The feed wheels 2, 4 are mounted on parallel spaced-apart shafts- 6, 8, these shafts in turn being mounted on the ends of "arms3, 5.which are pivotedat their left-hand ends on parallel spaced-apart shafts 7, 9, the shafts 7, 9 being fixed to'the machine frame or some other stationary structure. A spring ll' is attachedto the arms intermediate their ends and biases the feed wheels relatively towardseach other so that they will be in resilient engagement with the wire or wires being fedat all times. It will be understood that one of the shafts 6, 8 may be driven by an electric motor or thelike so that one wheel constitutes a drive wheel and the other wh eel constitutes an idler. i

Referring to. FIG. 3; the-wheel -2 may be of .the conventional type 'havinga hub 10 which is mounted on the shaft8fand a peripheral portion 12, the surface of which is-provided with circumferential grooves I4 adapted to receive the wir'esbeing fed. The wheel. 4 however has certain structural' feat'ures which permit the pair ofiwheels to successfully feed ,wires of different diameters as will be described below. l

The feed wheel 4 comp'rises a hub 16 which is mounted on the shaft 6 by means of fasteners 22'and 'a suitable clamping block as shown, a rim [8, and an intermediate section20iby meansof which the rim is integral with the hub. The rim portion 18 has a flange 24 on one side thereof which extends stopped. Lead making machines of the typeshown in U.S. Pat.

3,239,924 are commonly operated at speeds of up to 3,600 cycles per hour or :-cycles per minute and leads of 100 inches or more in-length are commonly produced. Only about onethird of the cycling time (about one-third of a second) is available for the wire feeding operation so that the feed wheels must be accelerated-to their maximum speed, must feed the required length of wire, and must be brought to a halt within a space of one-third 1- of a second. A torsionally resilient coupling, effective between the drive means for the feed wheel and the peripheral portions of the feed wheel,-would reduce the possibility of damaging the ,wires being fed during such rapid acceleration and deceleration.

It is accordingly an object of the present invention to provide an improved means for feeding two or more wires by means of a single pair of feeding wheels. A further object is to provide a dual wire-feeding means which can accommodate wires of grossly difierent diameters. A still further object is to provide a feed wheelsystem having a resilient. couplingtherein' to eliminate, or reduce, damage to the wire beingfed.

beyondthe peripheral surface 26 of the wheel and whichfunctions, in cooperation with a clamping plate 48, to hold or retain a pair of tires in spaced relation to the rim.

As best shown in FIG. 6', radially extending openings 28 are provided at-equal angular intervals on the surface 26adjaeent' to the flange 24'and' recesses 30 are provided onthe righthand side of the rimi=in alignment with the openings 28, the

'width of the recesses 30'being substantially equal to the diameters of the holes 28. The recesses 30 extend inwardlyfrom the side 32of'the' rim in the disclosed embodiment for. ease of manufacturing although, as will become apparent from the following description, the recesses 30 can. be replaced by drilled openings if desired.

A-pair of substantially identical tires 38, 40 are mounted on, and held in spaced-relationship to, thesurface 26 of the rim by means of a' plurality of pairs of compression. springs 32, 36. The spring 34 of each pair extends into one of the openings 28 while the spring '36 of each pair is received in the correspond ingrecess 30. The tires are provided with transversely extending grooves 41 on their inner surfaces, the angular spacing between adjacent grooves being the same as the spacing betweenthe adjacent openings 28 and recesses 30 inthe sur-' face 26'. i

The tires 38, 40 are'assembled to the wheel 2' by positioning the-several pairs of springs 34, 36 in the recesses and holes 30, 28 and merely positioningthe tires on the wheel with the outer endsof' the springs extending into the grooves 41 of the tires.

The tires are then clamped on the wheel by means of a clamp ing ring 48 which is positioned against the side 32 of the rim and held in position by suitable fasteners 50.

As shown best in FIG. 4, where the two wires being fed 52, 54 are of grossly different diameters the lefthand tire in FIG. 4 will be biased upwardly from the point of tangency of the two wheels so that this tire will be eccentric with respect to the axis of the shaft 6. When the feed wheels are at rest (or when they are running under steady state conditions), the springs 34, 36 will extend radially with respect to the axis of the shaft 6 and support the tires against the wires being fed with the wires centered in the grooves 42, 44 on the peripheries of the tires. During feeding, and regardless of any difference in diameters of the wires 52, 54, each revolution of the feed wheels will result in the feeding of equal lengths of the two wires because of the fact that both tires are rotated through a complete revolution by the wheels themselves and the tires have perimeters of equal length. The fact that the tire 38 is eccentrically disposed with relation to the axis of the shaft 6 does not, therefore, interfere with the feeding operation nor does it result in the feeding in a shorter length of wire than the length fed by the tire 40.

The two tires are made identical to each other when the wires being fed have the same nominal diameter and differ from each other only to the extent of the variations in diameter resulting from manufacturing tolerances. If the wires being fed are of different nominal diameters, so that one of the wires always has a greater diameter than the other wire, the groove in the tire which feeds the larger wire can be made larger than the groove for the smaller wire. Also, it may be desirable to change the outside diameter of the tire feeding the larger wire in order to compensate for the deeper groove therein.

Insofar as the ability of the feed wheel system shown to feed wires of different diameters is concerned, the invention provides a simplified structure as compared with prior art devices which can be manufactured at relatively low cost, which is highly reliable, and which can accommodate wires having substantially different diameters. The possibility of any slippage taking place between either of the tires and the wires 52, 54 is extremely remote because of the fact that the tires cannot move relative to the wheels (excepting by a limited amount which is discussed below) and are maintained in intimate resilient contact with the wires by the springs 34, 36 and by the spring 11.

As noted above, the disclosed embodiment of the invention also provides a resilient coupling between the driven feed wheel 4 and the tires mounted on this wheel. The effect of this resilient coupling is to permit the tires to rotate through a minor are relative to the wheel when a feeding operation is started and stopped. This resilient coupling is a highly desirable feature in that it cushions the effects on the wire of rapid acceleration and deceleration. For example, when the driven feed wheel is abruptly stopped at the end of a wire feeding, the wire is stopped by the wheel. Because of the fact that the wire has a relatively high inertia, a high frictional force is developed in the area of contact between the wheel and wire which can cause chafing or gouging of the wire insulation. When a torsionally resilient coupling is provided between the wheel and tires however, in accordance with the instant invention, the wire is brought to a stop more gradually than the feed wheel and the tires are displaced relative to the feed wheel with concomitant lateral deformation of the springs. It should also be noted that the resistance of the springs to such lateral deflection increases with the degree of deflection of the springs so that the stiffness of the resilient coupling increases as the speed of the wire is reduced. The effects of the frictional forces on the wire are thus spread over an increased length of wire (as compared to a stiff coupling) and damage to the insulation is minimized.

The manner in which the torsionally resilient coupling effect is achieved is illustrated in FIGS. 2 and 5. At the beginning of a wire feeding operation, the feed wheel will move ahead of the tires 38, 40 with concomitant lateral deflection of the springs 34, 36 as illustrated in FIG. 5. As the feed wheel picks up speed and as the tires begin to rotate with the feed wheel the springs will move the tires into alignment with the feed wheel and the springs will assume their normal radial positions with respect to the axis of the shaft 6 as shown in FIG. 2. At the end of the feeding cycle, and when the feed wheel is brought to an abrupt halt, the springs will again be deflected laterally but in the opposite direction from that shown in FIG. 5. The wire feeding operation will thus be brought to a steady and gradual halt and damage to the wires being fed will be avoided.

Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only.

I claim:

1. Wire feeding means forfeeding equal lengths of two wires simultaneously comprising:

a pair of feed wheels mounted on parallel spaced-apart axes,

one of said wheels having a pair of tires mounted on the rim portion thereof in side-by-side relationship, said tires being adapted to tangentially contact wires being fed by said wheels,

a plurality of spring means interposed between each of said tires and the said rim portion of said one wheel, said spring means being resiliently deformable in a radial direction, with respect to said one wheel, and in a lateral direction whereby,

wires having different diameters can be fed by said wheels with concomitant radial deformation of the spring means associated with the one of said tires in engagement with the larger diameter wire, and a torsionally resilient coupling is obtained between said one wheel and said tires by lateral deformation of said spring means.

2. Wire feeding means as set forth in claim I wherein said spring means comprises coil springs.

3. Apparatus as set forth in claim 2 wherein said rim portion of said one wheel has a plurality of pairs of side-by-side openings therein, said coil springs extending into said openings.

4. Wire feeding means for feeding equal lengths of two wires simultaneously comprising:

a pair of feed wheels mounted on parallel spaced-apart axes,

one of said wheels having a pair of tires mounted on the rim portion thereof in side-by-side relationship, said tires being adapted to tangentially contact wires being fed by said wheels,

resilient means interposed between said rim portion of said one wheel and said tires, said resilient means permitting independent angular and radial displacement of said tires relative to said one wheel thereby to permit feeding of wires of different diameters and to provide a torsionally resilient coupling between said one wheel and each of said tires. 

1. Wire feeding means for feeding equal lengths of two wires simultaneously comprising: a pair of feed wheels mounted on parallel spaced-apart axes, one of said wheels having a pair of tires mounted on the rim portion thereof in side-by-side relationship, said tires being adapted to tangentially contact wires being fed by said wheels, a plurality of spring means interposed between each of said tires and the said rim portion of said one wheel, said spring means being resiliently deformable in a radial direction, with respect to said one wheel, and in a lateral direction whereby, wires having different diameters can be fed by said wheels with concomitant radial deformation of the spring means associated with the one of said tires in engagement with the larger diameter wire, and a torsionally resilient coupLing is obtained between said one wheel and said tires by lateral deformation of said spring means.
 2. Wire feeding means as set forth in claim 1 wherein said spring means comprises coil springs.
 3. Apparatus as set forth in claim 2 wherein said rim portion of said one wheel has a plurality of pairs of side-by-side openings therein, said coil springs extending into said openings.
 4. Wire feeding means for feeding equal lengths of two wires simultaneously comprising: a pair of feed wheels mounted on parallel spaced-apart axes, one of said wheels having a pair of tires mounted on the rim portion thereof in side-by-side relationship, said tires being adapted to tangentially contact wires being fed by said wheels, resilient means interposed between said rim portion of said one wheel and said tires, said resilient means permitting independent angular and radial displacement of said tires relative to said one wheel thereby to permit feeding of wires of different diameters and to provide a torsionally resilient coupling between said one wheel and each of said tires. 